Perhaps you should try some spelling variations:
thuat bai » thuat bao, thuyet bai, thuat xay
nam thuc » nam thuoc, am thuc, nam thu
hai chau » lai chau, ha chau, hat chau
va thanh » gia thanh, ban thanh, va tinh
hai cau » hai chu, hai hau, hoi cau
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
ve nam » he nam, va nam, le nam

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thuat bai)) ky nang ma hoi. hieu ve nam thuc va thanh ((hai cau) OR (hai chau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat bai)) ky nang ma hoi. hieu ve nam thuc va thanh ((hai cau) OR (hai chau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuat bai)) ky nang ma hoi. hieu ve nam thuc va thanh ((hai cau) OR (hai chau)) tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat bai)) ky nang ma hoi. hieu ve nam thuc va thanh ((hai cau) OR (hai chau)) tren*.